DVDx encoding size problems

[happystab]

This is kind of a complicated problem. For some reason the movies I rip are comming out at way different bit-rates than what I have it set at. For example, I ripped a 1:40min movie at 112kbits but the finished product ended up 147kbits and was 850mb big. Conversly, I ripped a 2hour movie at the same bit-rate but the final product was only 79kbits and only 570mb in size. Does anyone know why i'm getting such a huge difference with the same setting, and does anyone have any suggestions on what to do about it. I am using DVDx ver. 2.3.

[guada]

Helo,

Have you tried to specify the size that you wish instead of the bitrate?
Surely as having taken the care to make the calculation of the audio.

[DrinkOrDie]

I'm assuming you are ripping a DVD to AVI or MPEG for PC watching and you want to fit it on a 700mb CD.

Thing is, you failed to mention what codec that you are using to encode your video stream. Also, are you using VBR encoding for the video or audio streams? Obviously, encoding both the audio and the video streams at a constant bitrate will produce a predictible output file size, but not necessarily the best quality.

Check individual settings for the codec you are using perhaps? You may find that your codec has a settings control window where you can further manipulate encoding perameters to create the desired size/quality balance.

When you choose your codec, also take a look at the settings for the codec. If your output file is comming out too large, make the necessary adjustment to your codec settings (lower the bitrate if quality result allows) in order to lower the output file size. Repeat if necessary to come as close as you can to the desired file size. Sometimes it just takes a little tweaking to find just the right setting.

[guada]

Hello DrinkOrdie,

You are right to specify it.
Me I thought that he had understood it. it is for it I invited him to choose the final size.
Thank you for this complement of information .

[happystab]

Specifying the file size works for movies that are decoded too large, but it does not work for ones that are decoded too small. I have tried adjusting the bitrate, and the codec (DivX 5.0.2) but nothing seems to work.

[happystab]

"encoded" my bad

[LordRPI]

Sometimes the file will come out smaller when the DivX codec does not need to make use of all that data.: it will only use as much data as it needs and it won't go higher. If you want to see how large you can go, turn off the profiles and encode at 1-pass quality based with the highest quality setting. This will give you the largest file size it can be. Compare the two sizes, and if they're similar, it's just because the codec didn't need any more bitspend.

[DrinkOrDie]

Happystab, your problem is indeed complicated. We are dealing with 2 different streams here. Video and Audio.

There are a number of reasons your output file can be larger or smaller than you expected. LordRPI has correctly stated one reason but there are so many more reasons why you are not getting the file size you expect. guada is also correct. Did you take into account that there is audio being encoded as well as video?

To tell you the truth, I just play it by ear. I mean, when I use DVDx, I usually have to guess a bit depending on what codec I choose to encode the output file. Here is where experience working with your codecs comes in handy.

Using DVDx, I usually use a 720X480 DVD NTSC DVD input.

Assuming that my DVD is as stated above, for my output settings, I choose a framerate that matches my DVD, and I choose a smaller output video size such as 480X352.

In other words, I take a large resolution video (720X480) and I shrink it down a bit to a smaller resolution and send that to the encoder. That gives your codec less to deal with, more bitrate for the amount of picture to encode.

I keep the audio at 48khz (no conversion) and encode it at 128kbs usually.

Do what I said above, and if your file comes out to large using Divx codec, then next time use the same settings but lower the encoding bitrate inside the divx codec settings, or lower your audio encoding bitrate. (Personally, I prefer Divx 4 or below, or Xvid). You can also try using virtualdub to cut out the credits and such, after encoding.

Remember that you are sending data from the DVDx program to your codec of choice. (divx) Your codec has it's own bitrate settings which you can adjust. The bitrate you choose will be a matter of choice. A balance between quality and keeping the file small. In order to keep a decent quality I recommend shrinking the video size like I said above.

You can also lower the bitrate of the audio encoder if audio quality is not so important to you, but leave the sampling rate at 48 if you want a faster encode.

If you don't quite understand all of that, just know this:
You are well on your way to understanding because you are asking the right questions!